Dear all,
I have 6 aspirated radiation shield (Young 41302) equiped with tachometer each (square wave, 2 pulses per revolution. TTL +5V). I've connected each tachometer on the following channels of a CR1000: P1, P2, C4, C6, C7 and C8.
C1, C2 and C3 are connected to an SDM-SIO1 (RS485 signal for 6 Vaisala HMP155A Temp/RH sensors) et C5 is used for SDI12 communication with 6 Gill WindSonic4 anemometer.
I monitor well the fanspeed on the P1 and P2 channels but nothing on the port coms?
I use the PulseCount command as following:
PulseCount (Fanspeed1, 1, 1, 0, 0, 1, 0)
PulseCount (Fanspeed2, 2, 1, 0, 0, 1, 0)
PulseCount (Fanspeed3, 14, 1, 0, 0, 1, 0)
PulseCount (Fanspeed4, 16, 1, 0, 0, 1, 0)
PulseCount (Fanspeed5, 17, 1, 0, 0, 1, 0)
PulseCount (Fanspeed6, 18, 1, 0, 0, 1, 0)
An idea of a possible problem?
Daniel
* Last updated by: Otemohu on 1/7/2013 @ 10:30 AM *
Up
As written above the program will not compile. It appears as if the Reps parameter and the channel parameter are swapped. Assuming you have written a program that will compile. Have you verified that the signal levels going in to the non pulse count (PC) channels are truly 0-5V? The PC channels don't require 0-5V, but the control ports (C1-C8) do.
* Last updated by: DAM on 1/14/2013 @ 3:48 PM *
Yes, you're right, I copied the program with errors. It did not in my real program.
It is possible the Dc current is not really 0-5V on control ports. I have to check that. Could you nevertheless say me how I can monitor the speed of fans without using control ports. Maybe I need a extension module?
We do offer a peripheral module, the SDM-INT8 which can perform the pulse counting on 8 channels. It will use C1-C3 for communications and can be used concurrently with the SDM-SIO1 you already have connected.
* Last updated by: DAM on 1/15/2013 @ 7:57 AM *
A good new.
Yes, I have just to change the SDM adress of the SDM-INT8 module (different from the one of SDM-SIO1).
We also offer the SDM-IO16 which has 16 channels and is a little cheaper. It only supports TTL signals though. You need to check if the likely frequency you need to measure though as the SDM-IO16 and SDM-INT8 have lower maximum frequencies than the pulse counter ports.
Currently, two of the six fans are connected to the two pulse port of the CR1000 and I record 4300 rpm (TTL 5V signal, 2 pulse per revolution.
4300 rpm is only 72 *2 [for the two pulses per rev] = 144 Hz which is well within the capabilities of the SDM-IO16 or SDM-INT8.
Hi Tracy,
The SDM-SIO1 is connected to SDM port on a CR1000 datalogger. Each RS485 HMP155A has a unique RS485 address that you have to configure first with a specific cable supplied by Vaisala.
In the CR1000, I write a loop FOR :
For i = 1 To 6
SerialOut (SensorPort,stringcom(i),"RH",3,100)
Delay(0,500,mSec)
SerialInRecord(SensorPort,SerialIndest(i),00,22,&H0D0A,NBytesReturned,00)
RHAir(i)=Mid (SerialIndest(i),2,5)
TempAir(i)=Mid (SerialIndest(i),14,5)
Next i
Cheers,
Daniel
* Last updated by: Otemohu on 9/10/2013 @ 2:25 AM *